Multiple-standard base stations have become a major trend in cellular communications networks. A multiple-standard base station is a base station that supports multiple Radio Access Technologies (RATs). A multiple-standard base station includes a digital baseband unit that supports multiple RATs and one or more radio units that wirelessly transmit and receive signals. Currently, the digital baseband unit for a multiple-standard base station includes separate resources for each of the RATs. More specifically, as illustrated in FIG. 1, a conventional digital baseband unit 10 for a multiple-standard base station includes separate cards, or circuit boards, for each of the RATs. Specifically, the conventional digital baseband unit 10 of FIG. 1 supports 3rd Generation Partnership Project 2 (3GPP2) 1x Radio Transmission Technology (RTT) for voice and 3GPP2 Evolution-Data Optimized (EV-DO) for data, where 3GPP2 1xRTT and 3GPP2 EV-DO are defined by separate Code Division Multiple Access (CDMA) standards and are separate RATs. The conventional digital baseband unit 10 includes a Control Module (CM) card 12-1 and a 1x card 12-2 that together support 3GPP2 1xRTT as well as a Data Only (DO) card 12-3 that supports 3GPP2 EV-DO. Each of the cards 12-1 through 12-3 has its own processing resources (e.g., Central Processing Unit (CPU) or Application Specific Integrated Circuit (ASIC)), its own memory resources, etc.
A primary concern for multiple-standard base stations is cost. Particularly for mature RATs such as CDMA RATs, the cards that support the RATs have been designed and re-designed to reduce cost and are now reaching the point where further reduction in cost is difficult to obtain. As such, there is a need for a new, or advanced, digital baseband unit that supports multiple RATs and significantly reduces the cost of the digital baseband unit and thus the cost of the multiple-standard base station.